[PATCH] D108076: [AArch64] Fix comparison peephole opt with non-0/1 immediate (PR51476)

[Nikita Popov via Phabricator via llvm-commits]

nikic created this revision.
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This is a non-intrusive fix for https://bugs.llvm.org/show_bug.cgi?id=51476 intended for backport to the 13.x release branch. It expands on the current hack by distinguishing between CmpValue of 0, 1 and 2, where 0 and 1 have the obvious meaning and 2 means "anything else". The new optimization from D98564 <https://reviews.llvm.org/D98564> should only be performed for CmpValue of 0 or 1.

For main, I think we should switch the analyzeCompare() + optimizeCompare() APIs to use int64_t instead of int, which is in line with MachineOperand's notion of an immediate, and avoids this problem altogether.


Repository:
  rG LLVM Github Monorepo

https://reviews.llvm.org/D108076

Files:
  llvm/lib/Target/AArch64/AArch64InstrInfo.cpp
  llvm/test/CodeGen/AArch64/csinc-cmp-removal.mir
  llvm/test/CodeGen/AArch64/pr51476.ll

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